Electrically-heated oven.



F. KUHN.

ELECTRICALLY HEATED OVEN.

APPLICATION FILED OCT. 31, 1914.

1 1 54,4 1 6 Patented Sept. 21, 1915.

WITNESSES: 1 X l/NVENTOR V9074 v raw z/fln 37 v M #MAZJ ZMLM FRANK KUHN, OF DETROIT, MICHIGAN.

ELECTRICALLY-HEATEI) OVEN.

Specification of Letters Patent.

Patented Sept. 21, 1915.

Application filed October 31, 1914. Serial No. 869,551.-

To all whom it may concern Be it known that I, FRANK KUHN, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Electri cally-Heated Ovens, of, which the following is a-specification, reference being had therein to the accompanying drawings.

The invention relates to electrically-heated ovens and comprises the novel construction and arrangement of parts as hereinafter set forth.

In the drawings: Figure l is a. perspective view of the oven with the shield removed; Fig. 2 is a transverse section; Fig. 3 is a plan view of the heating unit; Fig. 4 is a sectional view partlyin plan of the heating unit support.

It is the object of the invention to obtain a construction which is both inexpensive to manufacture and is-eflicient in its operation. To this end the oven is formed of an'outer sheet metal casing A and an inner casing B of rectangular form, spaced from each other and provided with suitable heat insulation 0 therebetween. The heating unit D is preferably formed by a naked coiled resistor E which is strung through insulator spools or knobs F supported on a frame G. The frame comprises merely straight bars of metal, which are spot-welded to each other at thepoints of crossing, their projecting ends G abutting against the walls of the oven and holding the resistor out of contact therewith. The frame is removably sup-- ported above the oven bottom by engaging the ends of the cross-barswith a grooved guide H, preferably of channel section. The insulator spools may be suspended from the frame by metallic clips I centrally spotwelded to the bars G and bent around the grooves in the spools. The terminal contacts J for the resistor are mounted upon an in- Sulator block K and are arranged to engage stationary contacts L in an insulator block M the oven and will cause the convection currents of heated air to pass upward along the side walls of the oven. To prevent interference with the ascending air currents, the shelves 0r gratings in the oven are spaced from the side walls thereof and are supported by guides N, preferably of channel section, secured to a vertical bar 0 preferably by spot-welding. This bar 0 may also form a securing means for the channel guide H, by which the unit frame is supported and the bars themselves may be secured either by bolting or by spot-welding or other suitable means to the walls of the oven. The shield P is placed over the frame G to protect the resistor, and the marginal portion of this frame is perforated, as at Q, for the passage of the convection currents. There is also a downturned flange R at the forward edge of the shield which protects the resistors when theoven door is open.

In use, the food to be cooked may be supported either upon the shield P or, preferably, upon shelves or gratings S which may be adjusted to different heights by-engagement with the p shelves are used the hot air will find access to the spaces therebetween by first passing upward through the clear space between the oven wall and the guides O and then passing laterally inward.

What I claim as my invention is 1. An electrically heated oven, comprising a casing, a frame formed of cross-bars fitting within the oven in a plane parallel to the bottom thereof, said cross-bars having projecting ends abutting against the walls of the casing, and a naked resistor extending around the margin of the frame substantially adjacent to said cross-bars and 'carried thereby.

2. An electrically heated oven comprising an oven casing having a door, a frame supported within said casing, a heating unit supported by said frame, and a shield upon said frame having a down-turned flange normally adjacent the door for protecting the heating unit.

3. An electrically heated oven, comprising a casing, a frame slidably detachably suspended within said casing and provided with insulator supports, a naked resistor susguides 0. Where several pended from said insulator supports in a In testimony WhereofI afiix my signature plane parallel to the bottom of the casing, in presence of two Witnesses.

. terminal contacts for said naked resistor, FRANK and statlonary contacts carried by sald caso 5 ing, said terminal and stationary contacts WitIlCIf:

being adapted to engage each other when the C. H. REUTELSTERZ,

unit is in place. ROLAND DRESSEL. 

